1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device. More particularly, the present invention relates to an LCD device and a method for fabricating the same, capable of preventing defects derived from a defective UV-curing of a sealant while employing one-drop fill technology.
2. Description of the Prior Art
As generally known in the art, a typical twisted nematic (TN) mode LCD device includes an array substrate formed with a metal signal line, a thin film transistor (TFT) and a pixel electrode, a color filter substrate formed with a black matrix, a color filter and a common electrode, and a liquid crystal layer interposed between the array substrate and the color filter substrate.
Herein, the liquid crystal layer is formed through a vacuum injection process employing osmotic pressure. However, as the LCD device has been fabricated in a large size, it becomes difficult to sufficiently inject liquid crystal between substrates through the vacuum injection process. In particular, the vacuum injection process requires a long time to inject liquid crystal between substrates, thereby causing limitations in terms of productivity.
In order to solve the problem of the vacuum injection process, one-drop fill (ODF) technology has been proposed. According to the ODF technology, a predetermined amount of liquid crystal is dropped onto the array substrate, and then the array substrate is combined with the color filter substrate, thereby forming the liquid crystal layer between the array substrate and the color filter substrate.
If the ODF technology is used in the fabrication process for the LCD device, the processes for injecting liquid crystal and assembling substrates are simultaneously performed, so the process time can be significantly reduced as compared with the vacuum injection process.
In order to employ the ODF technology, a UV-curing process for a sealant must be performed during the panel assembling process. However, the sealant coated on the metal signal line (e.g. a gate bus line, a common bus line and a data bus line) of the array substrate and the sealant coated on the black matrix of the color filter substrate may not be sufficiently UV-cured, thereby causing a problem or error when fabricating the panel.
To solve the above problems, conventionally, a slit is formed in the black matrix of the color filter substrate or the metal signal line of the array substrate so as to allow UV light to pass through the slit. In addition, a UV reflecting plate is provided in a UV radiation device so as to allow the UV radiation device to radiate the UV light in various angles.
Nevertheless, the UV light is not sufficiently radiated onto the sealant provided in a specific area, so that the sealant is not cured or incompletely cured, thereby causing the seal leakage and error when assembling the panels. For this reason, reliability and productivity of the panels may be lowered. In addition, the image quality of the LCD device is degraded.